Not to add more worry in these coronavirus times, but treating wetlands to kill mosquitoes to combat the diseases of Eastern Equine Encephalitis (EEE) and West Nile virus is scheduled to begin Monday, April 13 in Norfolk County.

Helicopters will be swooping down over parts of Foxboro, Plainville, Norfolk, Wrentham, Franklin and other area towns.

"The application is primarily an application to control the emergence of spring nuisance mosquitoes," said David A. Lawson, director of the Norfolk County Mosquito Control District.

The helicopters will be applying an insecticide targeting mosquito larvae in large wetlands, Lawson said.

The work will likely be conducted over a two- to four-day window, lasting only two days, anytime between April 13 and April 27, depending on weather.

"As usual, the weather in the spring is unpredictable," Lawson said. "For this reason, the district cannot pin down actual application dates with any more accuracy at this time."

Further notices will be sent out as the application date approaches.

"In light of the Covid-19 outbreak and all the complications surrounding that, the NCMCD has decided to alter our 'normal’ aerial application this year," Lawson said. "We will be removing some wetlands that have edges that very closely abut neighborhoods."

The intent of this change is to create a bit more of a buffer between the helicopters and the homes, he said.

"We receive very few 'complaints' each time we conduct these applications, but one of the most common complaints is about the low-flying helicopters over homes," Lawson said. "With stress levels already heightened, and more folks home during the application, we felt this was a prudent step to take."

Based on the best science available, the reduction in acreage will likely have no effect on the outcomes of EEE and WNV this summer, Lawson said.

The insecticide, which officials point out is not a spray, is biorational larvicide Bti (Bacillus thuringiensis israelensis). The trade name of the granular formulation of Bti to be used is VectoBac GR (EPA Reg. #73049-486).

For further information, contact Lawson at 781-762-3681 or the boards of health in the towns. Information is also available at www.norfolkcountymosquito.org.